UNIVERSITY    OF   CALIFORNIA 

COLLEGE   OF   AGRICULTURE 

AGRICULTURAL    EXPERIMENT   STATION 

BERKELEY,  CALIFORNIA 


THE  BLACKBERRY  MITE, 

THE  CAUSE  OF  REDBERRY  DISEASE 

OF  THE  HIMALAYA  BLACKBERRY, 

AND  ITS  CONTROL 

E.  O.  ESSIG 


BULLETIN  399 

December,  1925 


UNIVERSITY  OF  CALIFORNIA  PRINTING  OFFICE 

BERKELEY,  CALIFORNIA 

1925 


Digitized  by  the  Internet  Archive 

in  2012  with  funding  from 

University  of  California,  Davis  Libraries 


http://www.archive.org/details/blackberrymiteca399essi 


Fig.  1. — Branch  of  Himalaya,  blackberries  showing  a  typical  case  of  the  "redberry 
disease"  at  the  time  of  harvest.     Half  natural  size. 


THE  BLACKBERRY  MITE,1  THE  CAUSE  OF  REDBERRY 

DISEASE  OF  THE  HIMALAYA  BLACKBERRY, 

AND  ITS  CONTROL 

By  E.  O.  ESSIG* 


Specimens  of  Himalaya  blackberries  infected  with  what  is 
commonly  known  as  the  "redberry  disease"  were  first  received  by 
the  Division  of  Plant  Patholog3r  during  the  late  summer  of  1921.  A 
microscopic  examination  of  the  fruit  by  Miss  E.  H.  Smith,  Assistant 
Plant  Pathologist  in  the  Experiment  Station,  disclosed  a  minute 
white  mite  among  the  drupelets  and,  as  no  other  pathogenic  organism 
was  discovered,  the  specimens  were  placed  in  my  care  and  I  began 
a  study  of  the  problem,  to  ascertain  whether  or  not  the  mite  was 
in  any  way  connected  with  the  disease.  By  conducting  some  simple 
spraying  tests  with  lime-sulfur  and  wettable  sulfur  on  selected  plots, 
it  was  proved  that  when  the  mites  were  killed  the  redberry  conditions 
soon  disappeared.  Successive  tests  and  demonstrations  every  year 
since  1921  have  shown  that  the  mite  was  directly  responsible  for  the 
trouble  and  that  it  could  be  cheaply  and  effectively  controlled. 

THE  HOST  PLANT 

Observations  over  a  period  of  four  years  have  so  far  revealed  the 
mite  injurious  only  to  the  Himalaya  blackberry.  Other  varieties  of 
blackberries,  including  the  Mammoth,  Oregon  Evergreen,  Lawton,  as 
well  as  dewberries,  loganberries  and  raspberries,  growing  in  the  imme- 
diate vicinity  of  the  Himalaya,  and  often  interlacing  with  it,  have 
been  carefully  examined  without  finding  the  mite.  The  Mammoth 
blackberry  frequently  develops  a  redberry  condition  on  a  very  small 
scale,  but  this  has  usually  been  due  to  attacks  of  mealy  bugs,  thrips, 
and  other  insects.     So  far,  no  mites  have  been  found  in  such  berries. 

NATURE  OF  THE  WORK 

The  work  of  this  mite  is  best  characterized  by  the  common  term 
"redberry  disease,"  which  is  applied  to  the  red  condition  of  the  fruit 


*  Division  of  Entomology  and  Parasitology. 
1  Eriophyes  sp.    Family  Eriophyidae. 


4 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


at  harvest  time,  well  shown  by  the  accompanying  colored  plate  (fig.  1). 
The  mites  enter  the  flowers  and  infest  the  berries  as  the  drupelets  are 
forming,  and  remain  at  the  base  of  the  berry  and  about  the  core. 
They  feed  near  the  bases  of  the  drupelets,  causing  abortion  in  many 
cases,  a  retarded  and  uneven  ripening  in  some,  and  an  abnormal  red 
condition  in  the  great  majority  of  cases  (fig.  2).  A  few  berries  often 
remain  entirely  green  or  entirely  red,  while  some  are  to  be  found  with 
green,  red  and  fully  ripened  drupelets.  This  latter  condition  prevails 
generally  in  an  infestation  of  but  short  duration,  and  develops  into  the 


Fig.  2. — A  large  crop  of  Himalaya  blackberries  with  practically  100  per  cent 
infestation  of  the  blackberry  mite  and  none  of  the  berries  turning  black  at 
time  of  harvest.     (Photo  by  Paul  S.  Williamson.) 


characteristic  redberry  stage  in  one  or  two  more  years.  At  this  stage, 
the  infested  berries  remain  red  for  a  week  or  so,  then  dry  up  or  decay, 
but  never  ripen  in  the  normal  way.  The  dried  berries  may  remain 
on  the  bushes  until  the  following  season  (fig.  3).  In  three  or  four 
years  an  infestation  may  develop  to  the  extent  of  ruining  the  entire 
crop.  A  number  of  commercial  patches  and  many  backyard  plantings 
have  been  rendered  absolutely  worthless  by  this  obscure  mite.  In 
order  to  observe  the  mites  it  is  necessary  to  separate  the  drupelets  of 
the  suspected  berries  and  examine  them  under  a  good  hand  lens  or  pre- 
ferably under  a  microscope,  for  they  cannot  be  seen  by  the  unaided 
eye. 


Bull.  399' 


THE    BLACKBERRY    MITE    AND    ITS    CONTROL 


Fig  3. — Himalaya  blackberry  infested  with  the  blackberry  mite  and  showing 
the  last  season's  crop  dried  and  still  clinging  to  the  vine  on  the  18th  day  of 
February.     (Photo  by  Paul  S.  Williamson.) 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


THE   MITE 

The  mite  (fig.  4)  responsible  for  the  redberry  disease  is  an  unusu- 
ally small  species,  averaging  but  0.15  mm.  in  length,  and  is  but  one- 
fifth  as  wide.  The  color  is  translucent  white,  the  form  elongated 
cylindrical,  with  the  anterior  region  largest  and  tapering  almost  to  a 
point  at  the  posterior  end.  The  surface,  excepting  the  fore  part,  is 
finely  corrugated  with  seventy-five  or  eighty  fine  concentric  rings,  and 
supports  several  long  body  spines.  There  are  but  two  pairs  of  legs, 
situated  anteriorly,  which  serve  to  drag  the  body,  the  posterior  end 
of  which  is  controlled  by  means  of  a  sucker  which  serves  as  an  anchor 
when  needed.  The  feet  terminate  in  a  claw,  a  plumed  hair  and  a 
knobbed  hair  or  digitule,  as  shown  in  fig.  4. 


Fig.  4. — The  blackberry  mite,  Eriophyes  sp.,  which  is  the  cause  of  the  "red- 
berry  disease"  of  the  Himalaya  blackberry.  It  is  so  small  that  it  cannot  be  seen 
without  a  magnifying  glass.     Greatly  enlarged.     (Drawing  by  A.  8.  Hassan.) 

Specimens  of  the  mite  forwarded  to  Dr.  H.  E.  Ewing2  of  the 
Bureau  of  Entomology,  U.  S.  Department  of  Agriculture,  were  deter- 
mined as  the  European  species,  Eriophyes  gracilis  (Nalepa),  which  is 
common  on  the  European  raspberry,  Rubus  idaeus  Linn.,  in  Europe. 
Nalepa3  states  that  it  causes  a  yellow  erineum  on  the  tender  leaves,  but 
makes  no  mention  of  its  attacking  the  fruit.     Schlechtendal4  describes 


2  Essig,  E.  O.,  and  Smith,  E.  H.     Two  interesting  blister  mites.     Monthly  Bui. 
California  Dept,  Agr.  11:  63.     1922. 

Essig,  E.  O.     Note  on  the  two  blister  mites.     Ibid.  11:  466.     1922. 

3  Nalepa,  Alfred.     Zoologica  24:  236.     1911. 

4  von  Schlechtendal,  D.  H.  R.     Zoologica  24:  414,  fig.  15.     1911. 


BULL.  399]  THE    BLACKBERRY    MITE    AND    ITS    CONTROL  7 

similar  work  and  also  gives  an  illustration  of  a  raspberry  shoot  show- 
ing a  marked  curling  of  the  leaves,  with  no  mention  of  injury  to  the 
berries.  It  seems  hardly  probable  that  the  species  attacking  the  ber- 
ries of  the  Himalaya  blackberry  in  California  is  the  same  as  the  one 
infesting  the  leaves  of  the  European  raspberry  in  Europe,  but  as  yet 
the  writer  has  been  unable  to  account  for  its  presence  in  the  state. 
Further  study  may  reveal  the  true  source  of  its  origin. 

The  winter  is  spent  in  the  leaf  clusters  and  buds,  where  all  the 
protection  possible  is  available.  The  hibernators  consist  of  mature 
and  immature  forms,  which  remain  inactive  until  the  new  growth 
starts  in  the  spring.  As  the  flower  buds  appear,  the  mites  work  their 
way  into  the  unfolding  buds,  into  the  flowers  and  down  among  the 
developing  druplets  of  the  berries,  where  they  feed  until  the  fruit 
ripens,  rots,  or  dries  up  on  the  vines,  when  all  that  succeed  in  making 
their  way  to  the  leaf  clusters  and  buds  on  the  stalks  go  into  hiber- 
nating quarters.  The  small  white  oval  eggs  are  laid  in  the  berries, 
and  several  overlapping  broods  appear  during  the  summer  months. 

DISTRIBUTION 

The  distribution  of  the  blackberry  mite  in  California  appears  to 
be  coextensive  with  that  of  the  Himalaya  blackberry,  which  occurs 
chiefly  along  the  coast  (fig.  5).  Both  appear  to  thrive  best  in  a  cool, 
moist  climate  and  are  most  abundant  in  the  San  Francisco  Bay  region 
and  the  Santa  Cruz  foothills.  It  is  doubtful  if  there  is  a  single  com- 
mercial patch  or  a  backyard  vine  in  the  above  areas  that  is  not  now 
infested.  Infested  berries  have  been  received  from  practically  every 
county  along  the  coast,  but  serious  injury  has  not  yet  been  recorded 
in  the  extreme  south  or  north. 

CONTROLS 

Extensive  experiments  and  field  demonstrations  have  proved  that 
the  mite  can  be  effectively  controlled  by  the  application  of  early  spring 
sprays  and  that  infestations  and  injuries  may  be  completely  checked 
by  the  use  of  summer  sprays.  A  series  of  field  demonstrations  con- 
ducted by  Paul  S.  Williamson,  Assistant  Farm  Advisor  of  Santa  Cruz 
County,  in  commercial  plantings,  gave  excellent  proof  of  the  value  of 
the  sprays  recommended  for  control. 


5  Essig,  E.  O.     Preventing  redberry  disease.     Orchard  and  Farm,  Los  Angeles 
Examiner.     Apr.  15,  1923. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Lcrtituc/e  efCetfitOx/ 


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33°  N.  _ 
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Fig.  5. — Map  of  California,  showing  the  coastal  region  best  adapted  to  the 
culture  of  the  Himalaya  blackberry,  and  which  coincides  with  the  distribution  of 
the  blackberry  mite  and  the  "redberry  disease." 


BULL.  399]  THE   BLACKBERRY    MITE   AND   ITS   CONTROL  9 

Dormant  or  Early  Spring  Sprays  (fig.  6). — The  most  satisfactory 
results  are  obtained  by  the  application  of  dormant  or  early  spring 
sprays  to  kill  the  hibernating  forms  before  they  gain  entrance  into  the 
flowers  and  berries.  These  sprays  consist  of  commercial  lime-sulfur 
in  strengths  of  4  per  cent,  6  per  cent  or  8  per  cent,  or  corresponding 
strengths  of  dry  lime-sulfur  or  of  soluble  sulfur.  Apparently  the 
4  per  cent  is  as  satisfactory  as  the  stronger  solutions  if  spraying  is 
well  done.  The  improved,  highly  refined  lubricating  oil  emulsions  are 
also  satisfactory.  Applications  should  be  made  preferably  when  the 
new  growth  starts  in  the  spring  and  before  the  flowers  open.  Pruning 
and  trellising  should  precede  spraying.  Great  care  should  be  taken 
to  completely  cover  the  stems  and  buds  when  spraying. 


Fig.  6. — Kesults  of  spraying  demonstrations  in  the  control  of  the  blackberry 
mite  in  commercial  plantings  in  Santa  Cruz  County  by  the  Farm  Advisor.  Fruit 
sorted  at  the  time  of  harvest.  A,  vines  sprayed  on  March  4,  1924,  with  4  per 
cent  lime-sulfur;  normal  berries  484,  red  berries  16,  showing  but  3.2  per  cent 
redberry  disease  when  picked  on  August  4;  B,  vines  sprayed  on  March  4,  with 
8  per  cent  lime-sulfur;  normal  berries  494,  red  berries  6,  showing  but  1.2  per 
cent  redberry  disease  when  picked  August  4;  C,  check  vines  not  sprayed; 
normal  berries  395,  red  berries  105,  showing  21  per  cent  redberry  disease  when 
picked  August  4;  D,  vines  sprayed  May  4  with  4  per  cent  lime-sulfur;  normal 
berries  487,  red  berries  13,  showing  2.6  per  cent  redberry  disease ;  E,  vines 
sprayed  July  7  with  five  pounds  of  wettable  sulfur  to  one  hundred  gallons  of 
water;  normal  berries  474,  red  berries  26,  showing  4.2  per  cent  redberry  disease. 
(Photo  by  Paul  S.  Williamson.) 


10  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Blossom  and  Summer  Sprays. — Later  spring  sprays  of  either  4  per 
cent  lime-sulfur  or  of  wettable  sulfur,  applied  when  the  vines  are  in 
full  bloom,  are  nearly  as  effective  as  the  dormant  sprays,  according 
to  the  demonstrations  conducted  by  Mr.  Williamson  in  Santa  Cruz 
County.  The  usual  strength  of  wettable  sulfur  spray  is  five  pounds 
of  wettable  sulfur  to  one  hundred  gallons  of  water.  In  cases  of  severe 
infestations,  eight  pounds  of  the  wettable  sulfur  may  be  used.  Summer 
spraying,  if  done  when  the  berries  are  still  green,  may  result  in  check- 
ing the  work  of  the  mites  and  thus  allow  some  of  the  berries  to  mature 
normally.  Late  fall  spraying  is  often  too  late  to  affect  the  crop  of  the 
same  year  but  will  destroy  many  of  the  mites  and  thus  help  to  control 
the  pest  the  next  season.  Summer  or  fall  spraying,  followed  by  dor- 
mant spring  sprays,  will  insure  complete  protection.  To  prepare 
wettable  sulfur  sprays,  mix  dry  ten  pounds  of  milled  sulfur  or  flowers 
of  sulfur  and  one-half  pound  of  dry  calcium  caseinate  spreader.  Add 
sufficient  water  to  make  a  paste.  Place  in  the  spray  tank  and  add 
the  remainder  of  the  water  to  make  the  proper  dilution. 

Spraying  Insurance. — This  is  one  case  where  spraying  as  insurance 
may  be  justly  advocated  because  the  mite  is  so  generally  distributed 
and  control  measures  are  so  sure  to  bring  the  desired  results  that  the 
berry  grower  cannot  afford  to  run  the  risk  of  losing  even  a  part  of  the 
crop  by  failing  to  properly  treat  the  plants  in  the  early  spring. 

Spray  Injury. — So  far,  no  injury- to  the  vines  or  berries  has  been 
noticed  from  dormant  and  blossom  sprays,  even  where  the  concentra- 
tion of  lime-sulfur  has  been  as  high  as  8  per  cent.  Summer  sprays 
of  wettable  sulfur,  however,  have  caused  some  burning  to  the  leaves 
and  fruit  when  used  stronger  than  four  pounds  to  one  hundred  gallons 
of  water.  To  avoid  spray  injury,  apply  only  dormant  or  early  spring 
sprays,  or  irrigate,  if  possible,  before  the  application  of  summer 
sprays,  and  do  not  spray  during  excessively  dry  and  hot  weather. 

CONSUMPTION  OF  INFESTED  BERRIES 

Infested  berries  are  in  no  way  injurious  for  human  consumption. 
If  they  are  not  edible  fresh,  because  of  lack  of  ripening,  they  may 
be  safely  used  for  jams  and  jellies. 


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No. 
253. 

261. 

262. 

263. 
268. 
273. 

275. 


277, 
278. 
279, 
280, 

283, 
285. 
294. 
304, 

310. 
312. 
313. 

319. 
324. 

325. 


328. 
331, 
334, 

335. 

339. 

340. 

343. 
344. 

346. 
347. 

348. 
349. 

350. 

352. 

353. 
354. 
357. 

358. 
359. 


No. 
Irrigation   and   Soil   Conditions   in  the  361. 

Sierra   Nevada   Foothills,    California. 
Melaxuma    of    the    Walnut,     "Juglans  362. 

regia."  ■      363. 

Citrus   Diseases   of   Florida    and   Cuba 

Compared  with   Those  of  California.  364. 

Size   Grades   for  Ripe   Olives. 

Growing  and   Grafting  Olive  Seedlings.  365. 

Preliminary  Report  on  Kearney  Vine-  366. 

yard   Experimental   Drain. 
The     Cultivation     of     Belladonna     in  367. 

California. 
The  Pomegranate.  368. 

Sudan    Grass. 

Grain    Sorghums.  369. 

Irrigation   of   Rice   in   California. 
Irrigation    of    Alfalfa    in    the     Sacra-  370. 

mento  Valley.  3  71. 

The   Olive   Insects  of  California. 
The  Milk   Goat   in    California.  372. 

Bean   Culture  in   California. 
A   Study  of  the   Effects  of  Freezes  on  373. 

Citrus    in    California.  374. 

Plum    Pollination. 
Mariout  Barley. 
Pruning      Young      Deciduous       Fruit  375. 

Trees. 
Caprifigs    and    Caprification.  376. 

Storage  of   Perishable  Fruit  at  Freez- 
ing Temperatures.  377. 
Rice     Irrigation     Measurements      and  379. 

Experiments    in    Sacramento    Valley,  380. 

1914-1919. 
Prune    Growing   in    California.  381. 

Phylloxera-Resistant    Stocks. 
Preliminary    Volume    Tables    for    Sec-  382. 

ond-Growth   Redwood. 
Cocoanut    Meal    as    a    Feed    for   Dairy  383. 

Cows   and    Other   Livestock. 
The    Relative    Cost    of    Making    Logs  384. 

from   Small   and  Large  Timber. 
Control     of     the     Pocket     Gopher     in 

California. 
Cheese    Pests    and    Their    Control.  385. 

Cold    Storage    as    an   Aid  to   the   Mar-  386. 

keting  of  Plums. 
Almond    Pollination.  387. 

The  Control  of  Red  Spiders  in  Decid-  388. 

uous  Orchards. 
Pruning  Young  Olive  Trees.  389. 

A     Study    of    Sidedraft    and    Tractor  390. 

Hitches. 
Agriculture      in      Cut-over      Redwood  391. 

Lands. 
Further  Experiments  in  Plum  Pollina-  392. 

tion.  394. 

Bovine   Infectious   Abortion. 

Results  of  Rice  Experiments  in   1922.  395. 

A     Self-mixing    Dusting    Machine    for  396. 

Applying      Dry       Insecticides       and 

Fungicides.  397. 

Black    Measles,     "Water    Berries,     and 

Related    Vine   Troubles.  398. 

Fruit   Beverage    Investigations. 


Preliminary  Yield  Tables  for  Second 
Growth   Redwood. 

Dust   and   the  Tractor   Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Avocado  Culture  in  California. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in   Relation   of   Mouldy   Walnuts. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter 
Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and   Large   Timber. 

The  Cost  of  Producing  Market  Milk  and 
Butterfat  on  246  California  Dairies. 

Pear    Pollination. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,    1923. 

Sun-Drying  and  Dehydration  of  Wal- 
nuts. 

The   Cold   Storage  of   Pears. 

Walnut   Culture    in   California. 

Growth  of  Eucalyptus  in  California 
Plantations. 

Growing  and  Handling  Asparagus 
Crowns. 

Pumping  for  Drainage  in  the  San 
Joaquin    Valley,    California. 

Monilia  Blossom  Blight  (Brown  Rot) 
of  Apricot. 

A  Study  of  the  Relative  Values  of  Cer- 
tain Succulent  Feeds  and  Alfalfa 
Meal  as  Sources  of  Vitamin  A  for 
Poultry. 

Pollination    of    the    Sweet    Cherry. 

Pruning  Bearing  Deciduous  Fruit 
Trees. 

Fig   Smut. 

The  Principles  and  Practice  of  Sun- 
drying  Fruit. 

Berseem  or   Egyptian    Clover. 

Harvesting  and  Packing  Grapes  in 
California. 

Machines  for  Coating  Seed  Wheat  with 
Copper    Carbonate    Dust. 

Fruit    Juice    Concentrates. 

Cereal  Hay  Production  in  California. 
Feeding  Trials  with  Cereal  Hay. 

Bark   Diseases   of   Citrus  Trees. 

The    Mat    Bean     (Phaseolus    aconilifo- 

lius). 
Manufacture    of  Roquefort  Type  Cheese 
from    Gnat's    Milk. 

Orchard  Heating  in  California. 


CIRCULARS 

No.  No. 

87.   Alfalfa.  154. 
113.    Correspondence  Courses  in  Agriculture. 

117.  The    Selection    and    Cost    of    a    Small  155. 

Pumping   Plant.  157. 

127.   House    Fumigation.  160. 

129.   The   Control  of  Citrus   Insects.  164. 

136.  Melilotus    indica    as    a    Green-Manure  165. 

Crop  for  California. 

144.   Oidium    or    Powdery    Mildew    of    the  166. 

Vine.  167. 

151.  Feeding  and   Management  of   Hogs.  170. 

152.  Some  Observations  on  the  Bulk  Hand- 

ling of    Grain    in   California. 


Irrigation   Practice   in   Growing   Small 

Fruit    in    California. 
Bovine  Tuberculosis. 
Control  of  the  Pear  Scab. 
Lettuce  Growing  in  California. 
Small  Fruit  Culture  in   California. 
Fundamentals   of   Sugar   Beet   Culture 

under   California    Conditions. 
The   County   Farm  Bureau. 
Feeding    Stuffs    of    Minor    Importance. 
Fertilizing     California     Soils     for     the 

1918   Crop. 


No. 
173. 

178. 
179. 

184. 
190. 
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231. 
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233. 
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236. 


237. 

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241. 

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244. 
245. 
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249. 
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251. 


252. 
253. 
254. 

255. 


CIRCULARS — (Continued) 
No. 


The  Construction  of  the  Wood-Hoop 
Silo. 

The   Packing  of  Apples   in   California. 

Factors  of  Importance  in  Producing 
Milk  of  Low  Bacterial   Count. 

A   Flock   of    Sheep   on  the   Farm. 

Agriculture  Clubs  in   California. 

Onion    Growing   in    California. 

County  Organizations  for  Rural  Fire 
Control. 

Peat   as   a   Manure   Substitute. 

The  Function  of  the  Farm  Bureau. 

Suggestions  to  the  Settler  in  California. 

Salvaging    Rain-Damaged    Prunes. 

Seed  Treatment  for  the  Prevention  of 
Cereal  Smuts. 

Feeding  Dairy  Cows  in  California. 

Methods  for  Marketing  Vegetables  in 
California. 

Unfermented   Fruit   Juices. 

Vineyard  Irrigation  in  Arid  Climates. 

Testing  Milk,  Cream,  and  Skim  Milk 
for  Butterfat. 

The    Home    Vineyard. 

Harvesting  and  Handling  California 
Cherries    for    Eastern    Shipment. 

Artificial    Incubation. 

Winter  Injury  to  Young  Walnut  Trees 
during  1921-22. 

Soil  Analysis  and  Soil  and  Plant 
Inter-relations. 

The  Common  Hawks  and  Owls  of 
California  from  the  Standpoint  of 
the  Rancher. 

Directions  for  the  Tanning  and  Dress- 
ing of  Furs. 

The  Apricot  in  California. 

Harvesting  and  Handling  Apricots 
and  Plums  for  Eastern  Shipment. 

Harvesting  and  Handling  Pears  for 
Eastern   Shipment. 

Harvesting  and  Handling  Peaches  for 
Eastern   Shipment. 

Poultry   Feeding. 

Marmalade  Juice  and  Jelly  Juice  from 
Citrus  Fruits. 

Central  Wire  Bracing  for  Fruit  Trees. 

Vine   Pruning   Systems. 

Colonization    and    Rural   Development. 

Some  Common  Errors  in  Vine  Prun- 
ing and  Their  Remedies. 

Replacing    Missing    Vines. 

Measurement  of  Irrigation  Water  on 
the  Farm. 

Recommendations  Concerning  the  Com- 
mon Diseases  and  Parasites  of 
Poultry   in   California. 

Supports  for  Vines. 

Vineyard  Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter    Egg    Production. 

Leguminous  Plants  as  Organic  Fertil- 
izer   in    California    Agriculture. 


256. 
257. 
258. 
259. 
260. 

261. 
262. 
263. 
264. 

265. 


The   Control   of   Wild   Morning   Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning   Deciduous   Fruits. 

Pear  By-products. 

A  Selected  List  of  References  Relating 

to  Irrigation  in  California. 
Sewing  Grain  Sacks. 
Cabbage  Growing  in  California. 
Tomato  Production  in  California. 
Preliminary      Essentials      to      Bovine 

Tuberculosis  Control. 
Plant   Disease   and   Pest   Control. 

266.  Analyzing     the     Citrus     Orchard     by 

Means   of    Simple   Tree   Records. 

267.  The  Tendency  of  Tractors  to   Rise  in 

Front;    Causes   and   Remedies. 

268.  Inexpensive  Labor-saving  Poultry  Ap- 

pliances. 

269.  An  Orchard  Brush  Burner. 

270.  A  Farm  Septic  Tank. 

2  71.   Brooding    Chicks    Artificially. 

272.  California  Farm  Tenancy  and  Methods 

of  Leasing. 

273.  Saving  the  Gophered   Citrus  Tree. 

274.  Fusarium  Wilt  of  Tomato  and  its  Con- 
trol by  Means  of  Resistant  Varieties. 

Marketable  California  Decorative 
Greens. 

Home  Canning. 

Head,  Cane,  and  Cordon  Pruning  of 
Vines. 

Olive  Pickling  in  Mediterranean  Coun- 
tries. 

The  Preparation  and  Refining  of  Olive 
Oil   in    Southern    Europe. 

The  Results  of  a  Survey  to  Determine 
the  Cost  of  Producing  Beef  in  Cali- 
fornia. 

Prevention  of  Insect  Attack  on  Stored 
Grain. 

Fertilizing  Citrus  Trees  in  California. 

The   Almond   in   California. 

Sweet  Potato  Production  in  California. 

Milk  Houses  for  California  Dairies. 

Potato   Production   in   California. 

Phylloxera   Resistant  Vineyards. 

Oak  Fungus  in  Orchard  Trees. 


275. 


276. 

277. 


278. 
279. 


281. 


282. 

283. 
284. 
285. 
286. 
287. 
288. 
289. 

290.  The  Tangier  Pea. 

291.  Blackhead   and   Other   Causes  of  Loss 

of  Turkeys  in  California. 

292.  Alkali   Soils. 

293.  The    Basis    of   Grape    Standardization. 

294.  Propagation   of   Deciduous   Fruits. 

295.  The    Growing   and   Handling  of   Head 

Lettuce  in   California. 

296.  Control     of     the     California     Ground 

Squirrel. 

297.  A  Survey  of  Beekeeping  in  California; 

The  Honeybee  as  a  Pollinizer. 

298.  The    Possibilities    and    Limitations    of 

Cooperative  Marketing. 

299.  Poultry   Breeding:   Records. 

300.  Coccidiosis  of  Chickens. 


The  publications  listed  above  may  be  had  by  addressing 

College  of  Agriculture, 

University  of  California, 

Berkeley,  California. 

10m-12,'25 


